On April 29, 2020, the FDA approved Zejula (niraparib; from GlaxoSmithKline), an oral PARP inhibitor, as the first PARP inhibitor approved for first-line maintenance (long-term) therapy for all patients with advanced ovarian cancer (including epithelial ovarian, fallopian tube, or primary peritoneal cancer) whose cancer had a complete or partial response to platinum-based chemotherapy. Zejula was previously approved for several types of ovarian cancer, including patients with HRD-positive disease, defined by the presence of the BRCA gene mutation or genomic instability.
Since late 2018, women with ovarian cancer and a BRCA mutation whose cancer responded to initial treatment with chemotherapy were eligible to receive treatment with a PARP inhibitor, including Zejula or Lynparza (olaparib).
This approval was based on the results of a clinical trial of 733 patients with ovarian cancer who had a response to first-line platinum-based chemotherapy. Patients received first-line maintenance treatment with Zejula or with placebo.
The results showed significantly longer time without cancer progression in patients who received Zejula compared with patients who received placebo, regardless of HRD status. The average time without cancer progression in patients with HRD-positive status was 21.9 months with Zejula versus 10.4 months with placebo. The average time without cancer progression in all the patients was 13.8 months with Zejula versus 8.2 months with placebo.
The most common side effects with Zejula in the PRIMA study were thrombocytopenia (reduced platelets), anemia, nausea, fatigue, neutropenia, constipation, muscle pain, headache, insomnia, vomiting, dyspnea, decreased appetite, dizziness, cough, hypertension, and kidney injury.
